Question: How many significant figures does $04.04500$ have?
Answer: Identify the non-zero digits and any zeros between them. These are all significant. $0{4.045}00$ Leading zeros are not significant. $\color{orange}{0}{4.045}00$ Since there is a decimal, trailing zeros are significant. $\color{orange}{0}{4.04500}$ Counting all the significant digits gives us 6.